This long range interdisciplinary program concerns urgent problems of membrane biology, relating to the differences between normal and neoplastic cells. In the next grant year, we will emphasize the following direction: 1) Use of recently developed, automated cell culture methods, providing approximately physiological conditions insofar as pH, pO2 and pCO2 are concerned, applicable for either multisample or mass-monolayer cell production, in vitro irradiation under highly controlled conditions and monitoring the radiation effects, expecially of pO2; 2) Rational fractionation and subfractionation of the plasma membranes of normal and neoplastic cells, whether irradiated or not, especially by the use of ultracentrifugal "affinity" fractionation methods, newly developed; 3) Fractionation of membrane proteins from normal, neoplastic and irradiated cells and application of novel, macromolecular, antigenic reagents for covalent membrane labelling; 4) Study of the biosynthesis of plasma membrane proteins in normal, neoplastic and irradiated cells; 5) Use of infrared- laser-Raman - and CSR spectroscopy in the study of membrane changes in neoplasia.